Hitherto, ball valves have been generally prepared for a manual type or an automatic type respectively, and separately used in accordance with the purpose thereof.
In the case of a manual type, a ball valve is opened and shut by manually rotating a handle mounted on a spindle borne in a neck portion of a valve body so as to rotate a valve ball, while in the case of an automatic type, the ball valve is opened and shut in the same manner as above by rotating the spindle by an actuator mounted on the upper portion of the valve body.
However, separately preparing the valves of both types results in a higher manufacturing cost, and there is a further problem when a manual type ball valve mounted on a pipe line is converted to an automatic type, in that the ball valve must be wholly replaced. In order to solve such problems, study has been carried out to convert the manual type ball valve to the automatic type while using the valve body of the former, and an example of the above is disclosed in Japanese Unexamined Utility Model Publication No. 62-69677.
According to the valve disclosed in the above Publication, a mounting body is secured to a manual type (ball) valve body and grips the valve body from the upper and lower sides thereof to form a mounting device, and an actuator is attached to the thus-formed mounting device to convert the valve into an automatic type.
In the valve of the above type, however, there are the following problems:
a mounting device is necessary when the actuator is attached; PA1 the actuator may deviate from center because it is not directly secured to the valve body; PA1 the operation of the actuator may become unstable due to loosening of the mounting device; PA1 a separately-prepared saddle is necessary for fixing a pipe directly connected to the valve body; and PA1 a mount is necessary for a panel piping.
Also, another example of a ball valve capable of being changed from a manual type to an automatic type is disclosed in Japanese Unexamined Utility Model Publication No. 62-66072.
In the ball valve disclosed in the above publication, an actuator is secured to a ground portion via a frame, the ground portion separated from a valve body is mounted on the valve body so that the ground portion can be used as a mounting bed for the handle or the actuator. Thus, there are problems in that additional parts such as the ground portion and the frame are necessary, and the structure of the ball valve becomes relatively complicated.